Dumbbell



FIG. 1 is an isometric view of the dumbbell of the present invention;

FIG. 2 is a side view of the dumbbell of FIG. 1;

FIG. 3 is another side view of the dumbbell of FIG. 1, the dumbbell rotated 45 degrees from FIG. 2; and,

FIG. 4 is an end view of the dumbbell of FIG. 1, the opposite end view being a mirror image thereof. 

CLAIM The ornamental design for a dumbbell, as shown and described. 